Allright so i download some mml plugins, for donation, guestbook and shoutbox. What do i need to do with them, they are .php files. I don't have any database by the way i upload my files for manialink on fileden and im using Manialink designer. So please help me, im really noob at this

You are a bit required to have a host with php support at first. Either host yourself or use a php host. Fileden won't go with that. Mysql support is nice as well.
After that you need to open the files in notepad, not using 'manialink designer'. If you want dynamic content, a 'manialink designer' is (almost) useless.